In the operation of spark-induced combustion engines, and particularly automotive engines operating on gasoline, the octane rating of the fuel must be high enough to prevent knocking. Gasolines sold at service stations typically have an octane rating of from about 87 to about 93. Fuels having such octane ratings are satisfactory for most automotive engines.
For high performance engines, and for racing engines in particular, fuels of even higher octane ratings are required. The production of fuels of progressively higher octane values is progressively more difficult to achieve. In particular, fuels of octane value at or above 100 are highly desired and the most difficult to produce. This is particularly true for unleaded fuels.
A need exists for unleaded fuel compositions having high octane ratings.